Worked on this for a while, though I was having difficulty with the background, so I decided to doctor up a photo and make it look like the characters were included into it.

Meet Götthardt (left) and Arthur (right).

Worked a little more with textures, made the flat colors stand out I think. I gave the picture a bit of a focus blur to keep attention on the characters, adding a bit of depth. Shaded the books to make them more apart of the scenery and added the slight reflection of Arthur's foot against the polished wood.

Hope I did em justice! Constructive feedback is welcomed!

Götthardt is ©
Arthur is ©